The present invention relates generally to a system in combination with a fluid transfer conduit for closing off said conduit and simultaneously venting a remaining conduit segment to prevent spillage of subsequently disconnected conduit members.
Of increasing acceptance is the periodic removal of liquid sludge from sewage treatment facilities, with the sludge being applied to farm land as a fertilizer. In such practice, large transport tanks are loaded at the sewage treatment facility for sludge delivery to farm locations whereat the sludge is transferred to spreader vehicles equipped with a tank of lesser size. For purposes of efficiency and sanitation, the transfer between the large transport tank and the smaller spreader tank must be accomplished in an expeditious manner with no spillage. Large diameter communicating conduits, several inches in diameter, are used to expedite transfer of the liquid sludge. One of said conduits must be vented after completion of sludge transfer to remove a sizable residual amount of sludge to avoid later spillage upon disconnection of the conduits. A further consideration is the timely shutting off of the sludge flow as the lesser sized spreader tank becomes filled to capacity. Toward this end existing transport and spreader tanks are equipped with level sensing devices in circuit with aural warning devices which indicate to the operator tank level and when certain valves are to be actuated. Such arrangements include costly valve components and more significantly rely on the operator to timely operate the valves and other transfer controls in proper sequence.